1. Field of the Invention
The present invention relates to a computer program product, system, and method for determining an availability score based on available resources of different resource types in a storage system to determine whether to perform a failure operation for the storage system.
2. Description of the Related Art
A storage server in a data storage environment may send a health status message to a manager of the storage environment which can cause the storage manager to swap operations to a secondary storage system mirroring data from the primary storage system sending the health message. For instance, in the International Business Machine Corporation's (“IBM”) Geographically Dispersed Parallel Sysplex® (GDPS)® storage system, a high severity message may cause a failover or hyperswap operation. HyperSwap® is an IBM product that provides continuous availability for disk failures by maintaining synchronous copies of all primary disk volumes on one or more primary storage systems to one or more target (or secondary) storage systems. (HyperSwap and GDPS are registered trademarks of IBM in countries throughout the world). When a disk failure is detected, code in the operating system identifies HyperSwap managed volumes and instead of failing the I/O request, HyperSwap switches (or swaps) information in internal control blocks so that the I/O request is driven against the secondary volume. Since the secondary volume is an identical copy of the primary volume prior to the failure, the I/O request will succeed with no impact to the program issuing the I/O request, which could be an application program or part of the operating system. This therefore masks the disk failure from the program and avoids an application and/or system outage. An event which causes a HyperSwap to be initiated is called a “swap trigger”.